Gordon Corera's new biography, The Spy in the Archive, tells the story of Vasili Mitrokhin, a Soviet archivist whose secret efforts to copy and smuggle thousands of pages of intelligence files inflicted unprecedented damage on Soviet espionage operations. Mitrokhin, an unassuming and often overlooked figure, spent decades working in the KGB archives, where he began to quietly record sensitive information after becoming disillusioned with the Soviet regime. His covert mission was driven by both personal grievances and moral outrage at the brutality he uncovered in the files he managed.

Despite his lack of operational experience and his reputation as a loner, Mitrokhin meticulously documented the inner workings of Soviet intelligence, hiding his notes for years before finally defecting to Britain after the collapse of the Soviet Union. His material exposed hundreds of spies and revealed the vast reach of Soviet espionage, though only a few were ever prosecuted. The biography explores Mitrokhin's complex motivations, his fraught relationship with his British handlers, and the immense impact his revelations had on the intelligence world.

Mitrokhin's legacy is one of both triumph and frustration: while he dealt a severe blow to the KGB, he remained dissatisfied with how his information was used and the focus of subsequent publications. Corera's book offers a detailed and personal look at the man behind one of the most significant intelligence leaks of the twentieth century.